Lifting device



3,429,286 LIFTING DEVICE Aldo Alghisi, Barbariga, Brescia, Italy Filed Mar. 23, 1967, Ser. No. 625,345

U.S. Cl. 11452 2 Claims Int. Cl. B63c 7/08, 7/10 ABSTRACT OF THE DISCLOSURE Background of the invention The present invention relates to a lifting device in general, and more particularly to a device for lifting loads submerged in a liquid. Still more specifically, the invention relates to a device for lifting loads lying on the bottom of oceans, lakes or rivers.

A variety of devices is known for the aforementioned purpose. However, all of these devices suffer from the disadvantage that they are very complicated and hence expensive, that they must be serviced and maintained by highly skilled specialists and operated by specially trained personnel and are therefore expensive in use, and that they cannot usually be put into use on short notice because of the generally extensive preparation required for placing them in operative condition.

Summary of the invention The present invention overcomes the disadvantages of the prior art.

More particularly, the present invention provides a device for lifting loads submerged in a liquid, which is simple and inexpensive to construct, not costly in maintenance or operation, and highly eflicient and reliable in use.

In accordance with one feature of my invention I provide a device for lifting loads summerged in a liquid, which comprises a support adapted to be ballasted so as to descend when placed into a body of liquid. The support in turn is provided with external load-engaging means provided thereon and which are adapted to engage a load to be lifted. Further, my device includes means for buoying the support to an extent requisite for lifting a predetermined load engaged by the load-engaging means, and such means for buoying the support includes conduit means extending from the support to the surface of the body of liquid.

The support may consist of rigid or non-rigid material, but will in every case have an inner chamber which can be filled with a gas when the support is submerged, to thereby provide the requisite buoyancy. Means for ballasting the support may be provided on the exterior of the support and released when the latter is submerged and when the time has come for it to rise to the surface in response to the introduction of gas into its chamber, or the ballast may consist of liquid of the body of liquid which is allowed to enter into the interior of the chamber through a suitable opening in the support when the latter is placed into the body of liquid. In the latter case, of

nitecl States Patent course, this liquid in the interior of the chamber will be expelled by the gas entering thereinto preparatory to buoying and consequent lifting of the support. Of course, another possibility is to use discrete ballast members, as in the first-mentioned case, but not to release them when the support is to rise, and instead simply to leave them on the support and to provide the latter with suflicient buoyancy to lift both the ballast and whatever load is engaged by the load-engaging means.

The support may he in shape of a suitable body of various different configurations, for instance a box or the like, or it may be in form of a bag or balloon which is inflated when submerged in the body of liquid to thereby rise to the surface thereof.

In any case, the device according to the present invention makes use of the principle of buoyancy first discovered by Archimedes.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

Brief description of the drawing FIG. 1 is a side-elevational section of a first embodiment of the novel device, showing the same submerged in a body of liquid;

FIG. 2 is a fragmentary view substantially similar to that of FIG. 1, but showing a somewhat modified device; and

FIG. 3 is a side-elevational section of yet a further embodiment of the novel lifting device.

Description of the preferred embodiments Discussing now the drawing in detail, and firstl FIG. 1, it will be seen that the device shown there comprises a member which is generally designated with reference numeral 1 and which in its broadest sense may be considered a support. It will hereafter be referred to, for the sake of convenience of identification, as a container 1 and it should be understood that various different materials Will be suitable for making such a container. In the embodiment of FIG. '1 as well as that of FIG. 2, the material used for making the container is assumed to be rigid and, as shown clearly in FIG. 1, the container comprises an internal chamber 2. The latter communicates via a conduit 3 which may be rigid or may be flexible, with a source of compressed gas illustrated in FIG. 1. The point of communication of the conduit 3 with the inner chamber 2 is in the upper wall of the container 1, that is at the top thereof. In the bottom wall the container 1 is provided with an opening 4 so that liquid can enter into the interior of chamber 2 when the container 1 is placed into a body of liquid. This is the condition in which the device is shown in FIG. 1. The exterior of the bottom wall of container 1 is provided with load-engaging means in form of two hooks 5 onto which a load lying on the bottom of a lake, a river or of the ocean can be secured. Of course, the hooks 5 are shown by way of example only and can be replaced with other load-engaging devices which also need not be provided on the bottom wall of the container 1, but can be provided for instance on the side walls thereof.

In any case, when the container 1 is placed into a body of liquid, the air contained in the interior chamber 2 flows out of the chamber 2 as the liquid of the body of liquid surrounding the container 1 enters the chamber 2 through the opening 4. The container 1 is thereby ballasted and sinks to the bottom of the body of liquid. Thereupon, the load is engaged with the load-engaging means 5, which can be accomplished either by divers or by manipulation of the load-engaging means itself if the same is perhaps in form of grappling devices which can be operated from the surface of the body of liquid by remote control. The main point is, of course, that the load-engaging devices are used for engaging whatever load is to be lifted when the container 1 has descended in the body of liquid as a result of being ballasted by liquid entering through the opening 4. Once the load is engaged, compressed gas is admitted through the conduit 3 into the inner chamber 2 and this of course expells the liquid out of the chamber 2 through the opening 4 in the bottom wall of the container 1. Having thus experienced a strong increase in its buoyancy, the container 1 now rises to the surface of the body of liquid, carrying with it the load engaged by the load-engaging means 5. Of course, the weight of the load which can be lifted in this manner depends upon the amount of buoyancy which has been provided for the container 1 by the introduction of compressed gas into the inner chamber 2 thereof. This must of course be calculated. The load to be lifted can be varied in dependence upon the volume of the chamber 2, as is well known. It is to be noted, however, that loads which can be lifted in this manner are quite considerable. Of course, in calculating the lifting capacity of the device it must be remembered that the weight of the load to be lifted, together with the weight of the container itself, must always be less than the weight of the liquid which is displaced.

The embodiment shown in FIG. 2 operates on the same principle as that shown in FIG. 1, and corresponds substantially to the same. It differs therefrom only in one respect, namely in that the container, here identified with reference numeral 1 and provided with an inner chamber 2, is provided in its bottom wall not only wit-h an opening 4 through which liquid may enter into the chamber 2' to cause the container 1 to descend in the body of liquid, but also with the inlet to a further conduit 7 which is connected with a suction pump 6 and which in turn is connected with a conduit 8. The operation of the embodiment shown in FIG. 2 is simply that, as compressed gas is admitted at the top of the container 1 into the chamber 2' through the conduit 3 (not shown since similar to that in FIG. 1), the liquid in chamber 2' is simultaneously evacuated through conduit 7 by the pump 6 which then expels it through the conduit 8 either below or at the surface of the body of liquid. Of course, the pressure of the compressed gas which is admitted through the conduit 3 must be in excess of the withdrawal capacity of the pump 6 so that the pressure prevailing within the chamber 2 always exceeds the external pressure of liquid in which the body of container 1' is submerged and also exceeds the withdrawal capacity of pump 6, to assure that new liquid cannot enter into the chamber 2' through the opening 4'. In other respects the embodiment of FIG. 1 is the same as that of FIG. 2 so that the latter need not be described more specifically.

Coming now to FIG. 3 it will be seen that this differs from FIGS. 1 and 2 in that it is not in form of a rigid container such as the containers 1 and 1', but in form of a flexible bag 9 of non-rigid material. This bag, which may be compared to a balloon, is completely closed except where it communicates with the inlet of a compressed-gas conduit 11 which in turn communicates with a source of compressed gas similar to that shown in FIG. 1 and hence not illustrated in FIG. 3. The bag 9 is arranged to define therewithin a chamber and it will be seen that the opening of the chamber 10 is sealed at the flange of the conduit 11. In fact, the flange and the wall of container 9 can be made integral if desired. The container of the embodiment in FIG. 3 will, of course, be introduced into a body of liquid in non-inflated condition and is caused to descend in the water or other liquid not by being allowed to fill with a portion of such liquid, but by having suitable ballast means secured thereto. Such ballast means is not shown since of course many different types of ballast and means of securing the same to a body such as that shown in FIG. 9 are well known. It is preferable that the ballast be releasable from the surface of the body of liquid, but this can of course also be accomplished by divers if desired. In any case, when the ballast has caused descending of the container 9 in the body of liquid, the ballast is released and compressed gas is introduced into the chamber 10 through the conduit 11, filling the chamber 10 and providing the container 9 with the necessary buoyancy to cause it to rise to the surface. Of course, suitable load-engaging means must also be provided on the container 9 so that by utilization of such load-engaging means the container 9 can be secured to the load to be lifted which will then be brought to the surface as the container line rises upwardly in the body of liquid as a result of its increase in buoyancy.

Naturally, many materials can be utilized for the containers 1 and 1' as well as for the container 9. Thus, plastic materials are available for making such containers, steel and other metals can be utilized and under certain conditions even wood can be used. Naturally, the use of rigid materials would preclude the construction of a container such as shown in FIG. 3 and, conversely, the construction of containers of the type shown in FIGS. 1 and 2 generally preclude the utilization of non-rigid material such as is used in FIG. 3. The latter, however, is not an inflexible condition for the construction of such container. It is not believed necessary to show different types of sources for compressed gas since, obviously, it is possible to utilize simply a pre-charged tank of compressed gas, just as it is possible to utilize a compressor. All of these possibilities are well known to those skilled in the art and present no obstacle in the construction of a device in accordance with the present invention.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of load-lifting devices differing from the types described above.

While the invention has been illustrated and described as embodied in a device for lifting loads submerged in a liquid, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to 'be protected by Letters Patent is set forth in the appended claims.

I claim:

1. A device for lifting loads submerged in a liquid, comprising a support adapted to be ballasted so as to descend when placed into a body of liquid, said support comprising a container defining an internal chamber having a top region and a bottom region and including aperture means communicating with said chamber so that liquid may enter into said chamber and constitute ballast for the container, said aperture means being at least in part provided at said bottom region of said chamber external load-engaging means provided on said support and adapted to engage a load to be lifted; means for buoying the support to an extent requisite for lifting a predetermined load engaged by said load-engaging means, said means including conduit means communicating with said top region of said chamber and extending from said support 5 6 to the surface of the body of liquid; and liquid-withdraw- References Cited ing means, including a conduit communicating with said UNITED STATES PATENTS aperture means at said bottom region of said chamber and a suction pump communicating with said conduit, for 284667 9/1883 M 114-54 withdrawing liquid contained in said chamber. 5 1 3 3 3; 6 2. A device as defined in claim 1, said aperture means 2682246 6/1954 Best including at least two apertures, and said liquid-withdrawing means communicating with one of said apertures. ANDREW H. FARRELL, Primary Examiner. 

